INSECT POWDER. 



35 



In another i)lace (282, p. 167) Unger has recorded the results 

 shown in Table 10. 



Table 10. — Chemical anah/sis of insect, powders and flowers Jrom Dalmatia ( Unger). 





Product. 



Determination. 





Sample 

 No, 



Moisture. 



Ash on 



w&ter- 



free 



basis. 



llemarks. 



1 





Per cent. 

 8.56 



Per cent. 

 8.33 



No manganese; barium chromate and stems 

 present. 

 Do. 



9 



.. do 



3 



do 



7.3 

 6.74 



No manganese; much iron. 

 Strong in manganese. 



4 



Flowers from Spalato 8. 44 



From the fact that he found no manganese in Pyrethrum stems, 

 while it was always present in the flowers, Unger proposed to deter- 

 mine whether a powder was strongly adulterated with stems by test- 

 mg for manganese. Thorns (274), in 1890, however, found manganese 

 in the ash of C. leucanthemum and P. indicum, and Siedler (258) 

 showed that Pyrethrum stems are not entirely manganese-free. 

 Appreciable quantities of manganese in Pyrethrum stems from 

 Japan have been found by the authors.^ Unger's test is of no value. 



Thoms (274), in 1890, reported an ash content of 6.93 per cent in 

 whole flowers of C. cinerarisefolium, and one of 6.94 per cent in the 

 same after powdering. He (275) would determme the value of an 

 insect powder by a determination of its ash and petroleum-ether ex- 

 tract, together with a microscopical examination. From Dalmatian 

 insect powder which had been dried at 100°, Thoms obtained by ex- 

 tracting with petroleum ether 5.34 per cent of a brown-yellow extract 

 (dried at 80°), which had a strong odor of insect powder. Other 

 powders gave from 5 to 3.89 per cent. An adulterated insect pow- 

 der gave only 3.83 per cent extract, without the characteristic odor. 

 Flowers of Chrysanthemum, leucanthemum. (Hungarian daisy) yielded 

 4.02 per cent extract. 



The Chemist and Druggist for March 22, 1890 (17), reports an ash 

 content of 6 per cent on a sample of insect powder prepared from 

 flowers grown in Gippsland, the southeastern district of Victoria, 

 Australia. 



Eymard (77), 1890, gives the analysis of Pyrethrum powder 

 hownin Table 11. 



1 Manganese was determined in the various grades of insect flowers and stems of both Dalmatian and 

 apanese origin, the following average amounts being found: Japanese stems, 0.0123 per cent; Dalmatian 

 tems, 0.0077 per cent; Japanese closed flowers, 0.0155 per cent; Dalmatian closed flov.-ers, 0.0096 per cent; 

 Dalmatian open flowers, 0.0076 per cent. The manganese content of both stems and flowers varies so 

 Teatly and differs so little in the two parts of the plant that any method for estimating the amount of 

 )owdered stems in an insect powder from a determination of its manganese content is valueless. 



